A Florida woman has become the fourth in recent weeks to accuse veteran actor Bill Cosby of giving her pills that made her feel groggy, then forcing himself on her.

Therese Serignese, now 57 and a nurse in Boca Raton, said the TV star raped her in 1976 when she was 19 after a show in Las Vegas.

She said she went backstage and when the two were alone, Cosby gave her two pills and a glass of water, saying: "Take these."

"My next memory is clearly feeling drugged, being without my clothes, standing up," she said. "Bill Cosby was behind me, having sex with me."

Cosby spokesman David Brokaw did not respond to a request for comment.

Cosby's lawyer, in a statement released on Sunday, criticised previous "decade-old, discredited allegations", stating that "the fact that they are being repeated does not make them true".

Dozens of Cosby's television and comedy colleagues have either refused to comment or not returned telephone calls from the media in recent days.

The allegations by Ms Serignese and three others are similar.

:: Barbara Bowman, an aspiring actress, said in a November 13 Washington Post column that she was 17 and blacked out after Cosby drugged her, waking up to find herself in panties and a man's T-shirt with the actor looming over her. She said she was certain she was raped.

:: Joan Tarshis said on Monday she was a 19-year-old who wanted to be a comedy writer when Cosby gave her a drink and forced her to perform oral sex on him.

:: Actress and model Janice Dickinson told Entertainment Tonight on Tuesday that Cosby had given her red wine and a pill when they were together in a Lake Tahoe, California, hotel room in 1982. Cosby's lawyer, Martin Singer, said Dickinson's claims were "false and outlandish".

In addition, Tamara Green wrote an opinion piece on Wednesday for Entertainment Tonight. In 2005 she claimed publicly that she was drugged and Cosby attempted to assault her. Cosby's lawyers have previously denied they knew each other.

Ms Serignese says after the alleged rape, she willingly stayed with Cosby in Las Vegas for some time, but could not specify how long or whether the two had sex again during their time together. The two also maintained sporadic contact for years after the alleged rape.

The attempt by Cosby, 77, at a career comeback has been collapsing in recent days as the abuse allegations resurfaced. This week Netflix said it was postponing a comedy special it had planned with him to be shown later this month, NBC said it was halting development of a sitcom with him and TV Land axed re-runs of The Cosby Show.

Ms Serignese said she made a statement to Philadelphia police in January 2005 describing her allegations and provided a copy to the Associated Press news agency. The agency could not confirm today that a report had been filed with the Philadelphia police department.

She had agreed to give evidence on behalf of Andrea Constand, a Pennsylvania woman who claimed she was sexually assaulted by Cosby and settled before the case went to trial.

Ms Serignese said yesterday she was standing in a Hilton gift shop when she felt someone approach her, put his arm around her and say: "Will you marry me?" When she turned around, it was Cosby. She said they had a friendly conversation and he invited her to the show.

Afterwards, she said she was escorted to the green room, where the alleged rape took place.

Ms Serignese said she returned to the hotel later and stayed with Cosby for numerous nights, though she said she could not remember precisely when or for how long. She said she also could not remember if they had sex again, but recalled other details, including an expansive penthouse suite with a sunken living room, pinball machine and Miles Davis records littered on the floor.

She said she eventually thought she might be pregnant and Cosby told her to leave.

Several years later, around 1980 or 1981, she said, Cosby invited her to Lake Tahoe, saying he wanted to give her Louis Vuitton luggage, but she declined. Years after that, she said, she reached out to him when he was performing in the Detroit area, where she said she went to his hotel room after the show. She said he had encouraged her to go back to school and could not remember whether the two had sex.

Her last contact with Cosby, she said, was in 1996. She had been badly hurt in a car accident and moved to Florida to live with a sister who contacted the comedian seeking financial support. He asked to speak with Ms Serignese, she said, and yelled at her, asking why she was calling him after so many years.

Ms Serignese said Cosby sent her 10,000 dollars (£6,400) via Western Union and a couple of days later, she said she received a second payment of 5,000 dollars (£3,200) from his management company, the William Morris Agency. She provided a letter from the management company signed by William Morris agent Tom Illius who represented Cosby at the time. Mr Illius died in 2011.

She said Ms Constand's lawyers agreed to represent her but she decided not to sue. A lawyer involved in the civil case could not comment because of the settlement's confidentiality clause.

"There's no DNA. There's no evidence. There was no cameras. There's no videotaping back then. There's no proof," Ms Serignese said. "It's just my word against Bill Cosby."

High Point University in North Carolina has removed Cosby's name from its board of advisers, the High Point Enterprise reported.

Meanwhile Cosby took his comedy show on the road in the Bahamas as the controversy raged.

He performed in a small theatre at the Atlantis resort in an event in aid of a women's service organisation.

Cosby made no mention of the sex assault allegations and stuck to his routine, including stories about his childhood growing up in the projects of Philadelphia.

There were few empty seats in the house and a few people gave him an ovation when he finished his set.

Some in the audience said the allegations against Cosby remained unproven and added that his performance was a benefit for what they felt was a good cause.